No description available.

No description available.

Thesis (PhD)--University of South Australia, 2004.

Orientador: Ricardo Antonio Ferreira Rodrigues / Banca: Orivaldo Arf / Banca: Rita de Cássia Félix Alvarez / Resumo: Os manejos de água e de nitrogênio são importantes para atender adequadamente as necessidades da planta de arroz. Em região com verão chuvoso, o manejo de água é função do regime das precipitações e das irrigações, as quais são realizadas para suprir os períodos de deficiência hídrica. Em relação à necessidade por nitrogênio, o mesmo pode ser suprido com aplicação no solo na forma mineral e, também pela utilização de bactérias capazes de fixar o nitrogênio atmosférico ou a combinação dos dois métodos. Por isso, o objetivo deste trabalho foi avaliar o efeito de lâminas de água, inoculação de sementes com Azospirillum brasilense e doses de nitrogênio em cobertura, utilizando como fonte nitrogenada o sulfato de amônio, no desenvolvimento, componentes de produção, produtividade e qualidade industrial de grãos de arroz de terras altas. O delineamento experimental utilizado foi o de blocos casualizados, em esquema fatorial 2 x 2 x 5, com quatro repetições. Os tratamentos consistiram na combinação de lâminas de água (irrigado + precipitação pluvial e não irrigado + precipitação pluvial), da inoculação das sementes (não inoculado e inoculado) e da adubação nitrogenada em cobertura (0, 25, 50, 75 e 100 kg ha-1 de N). A altura de plantas foi influenciada pelo manejo de água e pelas doses de nitrogênio testadas, mas não ocorreu acamamento de plantas. O manejo de água também influenciou o número de panículas m-2, a fertilidade dos colmos e das espiguetas, teor de nitrogênio na planta, nos grãos e na folha, massa de 100 grãos, massa hectolítrica e produtividade de grãos, além de reduzir o número de dias para o florescimento e a duração do ciclo da cultura. A inoculação das sementes com A. brasilense aumentou o número de colmos e número de panículas por metro quadrado. As doses de N testadas não interferiram na produtividade do arroz de terras altas / Abstract: The water and nitrogen management are important to adequately meet the needs of the rice plant. In the region with a rainy summer, the water management is a function of rainfall and irrigation which are made to meet periods of water stress. The nitrogen can be supplied with application to soil in mineral form and the use of bacteria capable of fixing atmospheric nitrogen or combination of two methods. Therefore, the objective of this study was to evaluate the water levels, seed inoculation with Azospirillum brasilense and nitrogen doses, in cover, in the development, production components, productivity and quality of grain of upland rice. A randomized block design was used in a 2 x 2 x 5 factorial scheme, with four repetitions. The treatments consisted in water levels (irrigation + rainfall and no irrigation + rainfall), seeds inoculation (uninoculated and inoculated) and nitrogen fertilization in cover (0, 25, 50, 75 and 100 kg ha-1 N). The high plants was influenced by water management and nitrogen doses tested, but there was no bedding plants. The water management also influenced number of panicles per square meter, the fertility of stems and spikelets, nitrogen content in plant, grains and leaf, mass of 100 grains, hectoliter weight and grain yield, and reduce the number of the days to flowering and duration of the crop cycle. The seeds inoculation with A. brasilense increased the number of stems and number of panicles per square meter. The nitrogen doses were tested did not interfere in yield of upland rice / Mestre

No description available.

Surface runoff is one of the most important problems which occur with moving sprinkler irrigation systems: it is particularly severe in centre pivot systems operated at low pressure. The consequences of surface runoff are waste of water, lower irrigation efficiency, soil erosion and removal of fertilizers from the field. An obvious indicator of the potential for runoff to occur during sprinkler irrigation is the appearance of surface ponding. Indeed, results from a stationary "time to ponding" test (using a minimum set of three constant water application rates) carried out on the farm, is commonly used to determine the irrigation rate in moving systems. This practice sometimes leads to the occurrence of runoff under moving systems, particularly centre pivot systems. / The primary aim of the investigation was to explore the phenomenon of soil surface ponding in stationary "time to ponding" tests (using constant water application rate) and in moving sprinkler irrigation systems (using variable water application rate), and to discover the relationship between these two sets of conditions, in order to improve the design and managements of these systems and avoid runoff. / A vital component of the investigation was the development of a laboratory rig which incorporated certain characteristics and properties, including: A special soil test bed containing 355mm depth of a loamy sand soil, together with a system continuously measuring and monitoring soil moisture content. The rig also included heating and suction systems to reduce and establish target soil moisture conditions before each test, and an efficient drainage system. Ponding was identified in 15 circular depressions on the soil surface. A water application simulator capable of being operated in both stationary and moving modes at different speeds, applying different constant and variable irrigation rates to the soil test bed with very small droplets. The nature of the supply closely approximated that of field installations. A continuous water application measurement device capable of measuring instantaneous water application rate and pattern as well as irrigation depth applied to the soil test bed. / Certain parameters, of necessity, were fixed for the investigation: these included the soil, the type of variable application pattern (parabolic), the range of speeds of the moving simulator (10% to 100% of maximum speed which was 345mm/minute) and the range of initial soil moistures (3% up to field capacity). Initial tests were carried out to determine a suitable water application rate: this was set as 103mm/h (average). The main set of tests was carried out using this average application rate under constant ("time to ponding") and variable ("onset of ponding") irrigation conditions at different soil moisture contents. / The main outcome of the research was that the maximum irrigation depth that can be applied by a moving system (variable pattern) without the appearance of ponding for any set value of initial soil moisture, is significantly less than the maximum irrigation depth which must be applied to produce ponding in a stationary system (constant pattern), operated with the same initial soil moisture and same average application rate. Therefore, the results obtained from a “time to ponding” test, if applied directly, overestimate the optimum water application rate and also the maximum irrigation depth which can be applied in moving irrigation systems, if they are to operate efficiently. / A relationship was established between the two sets of outcomes for corresponding soil and water application rate and pattern conditions. The apparatus and the method can be used for further research to discover similar relationships for different soil types and different water application rates and patterns in order to provide a general model. This model can be used to modify the optimum water application rate (obtained directly from stationary "time to ponding" tests) and, also, the maximum irrigation depth (through choice of speed appropriate to the initial soil moisture) in moving sprinkler irrigation systems, particularly in centre pivot systems. / Thesis (PhDCivilEngineering)--University of South Australia, 2005.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 232-241). Also available via the Internet

Made available in DSpace on 2014-06-11T19:23:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-05Bitstream added on 2014-06-13T18:50:26Z : No. of bitstreams: 1 guirra_appm_me_jabo.pdf: 278924 bytes, checksum: 904126f5d8e8dc9fa0c2d2c6db8f43da (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A maioria dos catálogos técnicos dos fabricantes não especifica, para as diferentes posições do defletor e pressões de serviço, o perfil radial de distribuição de água de seus aspersores, limitando-se à apresentação de valores de vazão e raio de alcance. Devido a ausência das informações (posição do defletor x pressão de serviço x espaçamento), neste trabalho teve-se como objetivo avaliar o desempenho do aspersor NaanDanJain, com bocal de 3,5 mm de diâmetro (cor azul), modelo 435 ½” M, operando com as pressões de 100, 200, 300 e 400 kPa, em cinco posições do defletor de ajuste (30º; 21,4º; 12,8º; 4,2º e 0º). Para a determinação dos parâmetros avaliados utilizou-se o método da malha, e com o auxílio do aplicativo computacional CATCH 3D calculou-se a sobreposição das lâminas de água com oito espaçamentos. A simulação da uniformidade de aplicação de água (CUC e CUD) apresentou melhores resultados para o espaçamento 6 x 6 m nas pressões de 200, 300 e 400 kPa. A utilização da pressão de 100 kPa resultou em menor uniformidade de aplicação para todos os espaçamentos ensaiados, sendo recomendadas pressões superiores a 100 kPa. As diferentes pressões e ângulos do defletor influenciaram o raio de alcance, o perfil de distribuição e a uniformidade de distribuição de água. As diversas combinações de ângulo do defletor e pressão de serviço possibilitaram a utilização do aspersor em diferentes condições operacionais / The most of manufacturer technical catalogs do not specify, to the different deflector position and work pressure, the water distribution radial profile of its sprinklers, limiting only the flow values and reach ray values presentation. Due to the lack of information (deflector position vs. work pressure vs. spacing) in this work it was evaluated the performance of the sprinkler NaanDanJain, nozzle with diameter 3.5 mm (blue), model 435 ½” M, working under pressure of 100, 200, 300, and 400 kPa in five deflector adjustment positions (30°, 21.4°, 21.8°, 4.2°, and 0°). To determine the evaluated parameters the mesh method was used, and with the computational application CATCH 3D the water depht overlap was calculated with eight replications. The water application uniformity simulation (CUC and CUD) presented better results to the 6 x 6 m spacing in the 200, 300, and 400 kPa pressures. The 100 kPa pressure use resulted in a lower spraying uniformity to all the evaluated spacing, being, this way, recommended pressures higher than 100 kPa. The different pressures and deflector angles influenced the operation range, the distribution profile, and the water distribution uniformity. The several deflector angle and work pressure combinations allowed use the sprinkle in different operational conditions

Made available in DSpace on 2014-06-11T19:29:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-10-14Bitstream added on 2014-06-13T18:39:38Z : No. of bitstreams: 1 moura_rs_me_ilha.pdf: 363425 bytes, checksum: 48c43d19cdd6885b5be63fdcc650f9fb (MD5) / Universidade Estadual Paulista (UNESP) / Os manejos de água e de nitrogênio são importantes para atender adequadamente as necessidades da planta de arroz. Em região com verão chuvoso, o manejo de água é função do regime das precipitações e das irrigações, as quais são realizadas para suprir os períodos de deficiência hídrica. Em relação à necessidade por nitrogênio, o mesmo pode ser suprido com aplicação no solo na forma mineral e, também pela utilização de bactérias capazes de fixar o nitrogênio atmosférico ou a combinação dos dois métodos. Por isso, o objetivo deste trabalho foi avaliar o efeito de lâminas de água, inoculação de sementes com Azospirillum brasilense e doses de nitrogênio em cobertura, utilizando como fonte nitrogenada o sulfato de amônio, no desenvolvimento, componentes de produção, produtividade e qualidade industrial de grãos de arroz de terras altas. O delineamento experimental utilizado foi o de blocos casualizados, em esquema fatorial 2 x 2 x 5, com quatro repetições. Os tratamentos consistiram na combinação de lâminas de água (irrigado + precipitação pluvial e não irrigado + precipitação pluvial), da inoculação das sementes (não inoculado e inoculado) e da adubação nitrogenada em cobertura (0, 25, 50, 75 e 100 kg ha-1 de N). A altura de plantas foi influenciada pelo manejo de água e pelas doses de nitrogênio testadas, mas não ocorreu acamamento de plantas. O manejo de água também influenciou o número de panículas m-2, a fertilidade dos colmos e das espiguetas, teor de nitrogênio na planta, nos grãos e na folha, massa de 100 grãos, massa hectolítrica e produtividade de grãos, além de reduzir o número de dias para o florescimento e a duração do ciclo da cultura. A inoculação das sementes com A. brasilense aumentou o número de colmos e número de panículas por metro quadrado. As doses de N testadas não interferiram na produtividade do arroz de terras altas / The water and nitrogen management are important to adequately meet the needs of the rice plant. In the region with a rainy summer, the water management is a function of rainfall and irrigation which are made to meet periods of water stress. The nitrogen can be supplied with application to soil in mineral form and the use of bacteria capable of fixing atmospheric nitrogen or combination of two methods. Therefore, the objective of this study was to evaluate the water levels, seed inoculation with Azospirillum brasilense and nitrogen doses, in cover, in the development, production components, productivity and quality of grain of upland rice. A randomized block design was used in a 2 x 2 x 5 factorial scheme, with four repetitions. The treatments consisted in water levels (irrigation + rainfall and no irrigation + rainfall), seeds inoculation (uninoculated and inoculated) and nitrogen fertilization in cover (0, 25, 50, 75 and 100 kg ha-1 N). The high plants was influenced by water management and nitrogen doses tested, but there was no bedding plants. The water management also influenced number of panicles per square meter, the fertility of stems and spikelets, nitrogen content in plant, grains and leaf, mass of 100 grains, hectoliter weight and grain yield, and reduce the number of the days to flowering and duration of the crop cycle. The seeds inoculation with A. brasilense increased the number of stems and number of panicles per square meter. The nitrogen doses were tested did not interfere in yield of upland rice

No description available.